Home Improvement Questions? Ask a Handyman for Answers
I have a Payne 394JAWO60095 gas furnace. When thermostat is turned on, it repeatedly runs for several minutes, then turns off, then runs several minutes, etc. Since it doesn't run continuously it takes many hours to warm the house. The filter is clean. The burners appear to be burning as they always have. Any thoughts?
1. Check to see if your thermostat has battery. The new ones take AA batteries. You have to open it by taking the front cover off. 2. You can locate a diagnostic code which is simply a flashing light. The new furnaces have this. Often the flashing code can be located by removing the top panel of the furnace and you will notice a blinking light inside somewhere on the control module. 3. Make sure all the covers are on and good. Sometimes a loose cover on the furnace will cause it to go on and off at random times. Please remember that this information is just a guide and in no way do I claim fault or liability if it doesn't work for you. If none of this works you may have a hardware issue and that will require more troubleshooting and work with a meter. Please provide the make and model of your furnace and the type of thermostat you have installed. ie : digital or bulb type
I have a digital thermostat. The batteries are good. The covers fit well and the cover safety switch is secure and works well. The furnace turns on for 3 minutes, then burners turn off and blower runs about 1 1/2 minutes during cool down cycle & then turns off. 30 seconds later the whole cycle repeats. This happens over & over until eventually it gets up to temp. Is there a high temp limiter that might be faulty and shutting it down before it gets up to temp? Or some other safety sensor that could be faulty?
Hi,Could you explain your situation a little more?
What is the make and model number of the furnace?When was the last time the furnace was professionally serviced?What is the age of the furnace?What fuel does the furnace use?What have you tried to correct the problem?Do you have a digital camera that you could use to send pictures of the furnace if needed?Thank you again for trusting us with your problem.
Please reply as soon as possible so that we can finish answering your question.
Payne 394JAWO60095 gas furnace. The furnace turns on for 3 minutes, then burners turn off and blower runs about 1 1/2 minutes during cool down cycle & then turns off. 30 seconds later the whole cycle repeats. This happens over & over until eventually it gets up to temp. About 15 years old. Serviced maybe 10 years ago. I replaced the batteries in the digital thermostat (even though old ones were still good). Removed the covers and checked the cover safety switch; checked for any obvious detached/frayed wires, or other visible defects. Cleaned the filter. I have a digital camera. Is there a high temp limiter that might be faulty and shutting it down before it gets up to temp? Or some other safety sensor that could be faulty?
There is a fan limit switch but that controls the blower. The flame sensor is a safety device that shuts down the furnace when it detects a problem. Click here for more information on the flame sensor.
Another safety feature that will shut a furnace down is the pressure switch if applicable. Another possibility is a dirty burner. The burner should be cleaned every heating season. The following links have more information on the topic.
Gas heater maintenance and troubleshooting
Trouble shooting a furnace
If this information does not help you correct the problem let me know and I will continue providing you the information to fix your furnace but then a picture of your furnace with the service door removed will be very helpful.
Should you require further clarification, never hesitate to ask. It would be my pleasure to clarify my answer to your question. If after reviewing the above information, you have additional questions, I will be glad to answer them. My goal is your 100% satisfaction with all questions I answer.
My furnace appears to have a combination electric ignition pilot/flame sensor in which the pilot is lit by the electric spark ignition, and then the pilot runs until the flame sensor confirms the heat and triggers the gas to flow to the burners, which then ignite from the pilot flame. This all seems to operate as designed, with an appropriate delay until the burners ignite. However, 3 minutes later the burners turn off and the blower runs through the cooling cycle. Then it starts over. It seems to make sense that a limit switch is shutting it down. I haven't checked the A-coil, but there seems to be good air flow from the vents.
Do you have a digital camera that you could use to send pictures of the furnace if needed?
Does your furnace have a draft inducer? This is a small blower that comes on before the burner will be lit.
A pictures of the inside of the furnace with the service door removed would be great. They can be posted here if you have the advanced tool bar available in the box that you type in. Image of the tool bar below.
You would need to click on the green icon that looks like a tree. If you do not see the tool bar you will need to click on the tool bar icon at the top of this page and select edit profile. From there you have the choice to check the advanced posting tools which will display the tool bar. The flame sensor on your furnace also has the spark igniter tip on the part. The flame sensor does need to be kept clean or it can cause the problem you are experiencing. Any deposits that are present will need to be removed with an abrasive like sandpaper or a wire brush. Once I get the images I will be able to provide you other information. Before the flame goes out, do you notice any movement or change it the color of the flame?
Well, I figured out the problem and I'm feeling pretty silly right now. I have an AirMedic filter that I just cleaned and put back in rather than disposing and replacing with a new one. When I last removed it about 2-3 weeks ago when I had been having this problem for about a week, it was quite dirty (probably because we have a dog now), and I thought that might have been the problem. I took the filter out and intended to clean and replace it, but never got to cleaning it....so there has not been a filter in for 2 weeks when I was thinking the cleaned filter was in. So today I finally realized the filter was not in and I cleaned and replaced it. It works fine......and I feel like a complete fool. I can only guess that with the dirty filter there was not enough airflow so the high temp blower sensor shuts things down repeatedly....and then without the filter in, the blower was able to move too much air and the low temp sensor shut it down. Does that make sense?
I want to thank you for your help and links to furnace operation. It helped me learn quite a bit.
I also wondered what you think would/should be included in a complete furnace cleaning/servicing, and about how much it would cost from a furnace/air cond company. It has been a long time since ours was serviced.
Thanks again. If I have future plumbing/electrical/general handyman questions, is there a way to direct them to you?
Yes, I believe you have described the problem very well. Normally service would include clean and lubricate the blower assembly, the pilot light assembly and the burners. In addition the bearings, the belt if applicable. Check for gas leaks and a cracked heat exchanger and the duct including the chimney. Since you indicate you have animals it is often advisable to have the air ducts cleaned. Something many people do not think about until there is a problem is the A coil and the coils in the unit on the outside for the air conditioner. These should be cleaned to insure efficient operation of both the heater and air conditioner. You can expect to pay $100 up depending on how much is done.
Many homeowners do not realize, the complications of not having a professional inspect the heating system yearly, can cause. If a fire, or worse, is caused by the furnace and there are no records of the furnace being maintained, the insurance company can and will deny the claim for damages. I have worked on systems after they have caught fire and the homeowners got no help from their homeowners insurance for the damage. I have installed furnaces in new homes that the owners were building to replace a home that was destroyed by fire from not having the furnace serviced. I like every customer to have this information to consider before repairing the furnace themselves.
If you have additional questions I will be glad to answer them. I hope you will return to Just Answer again.